// SPDX-License-Identifier: GPL-2.0
/*
 * Magnachip d53e6ea8966 MIPI-DSI panel driver
 * Copyright (C) 2023 Chris Morgan
 */

#include <drm/drm_mipi_dbi.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_modes.h>
#include <drm/drm_of.h>
#include <drm/drm_panel.h>

#include <linux/backlight.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/media-bus-format.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>

#include <video/mipi_display.h>

/* Forward declaration for use in backlight function */
struct d53e6ea8966;

/* Panel info, unique to each panel */
struct d53e6ea8966_panel_info {
	/** @display_modes: the supported display modes */
	const struct drm_display_mode *display_modes;
	/** @num_modes: the number of supported display modes */
	unsigned int num_modes;
	/** @width_mm: panel width in mm */
	u16 width_mm;
	/** @height_mm: panel height in mm */
	u16 height_mm;
	/** @bus_flags: drm bus flags for panel */
	u32 bus_flags;
	/** @panel_init_seq: panel specific init sequence */
	void (*panel_init_seq)(struct d53e6ea8966 *db);
	/** @backlight_register: panel backlight registration or NULL */
	int (*backlight_register)(struct d53e6ea8966 *db);
};

struct d53e6ea8966 {
	/** @dev: the container device */
	struct device *dev;
	/** @dbi: the DBI bus abstraction handle */
	struct mipi_dbi dbi;
	/** @panel: the DRM panel instance for this device */
	struct drm_panel panel;
	/** @reset: reset GPIO line */
	struct gpio_desc *reset;
	/** @enable: enable GPIO line */
	struct gpio_desc *enable;
	/** @reg_vdd: VDD supply regulator for panel logic */
	struct regulator *reg_vdd;
	/** @reg_elvdd: ELVDD supply regulator for panel display */
	struct regulator *reg_elvdd;
	/** @dsi_dev: DSI child device (panel) */
	struct mipi_dsi_device *dsi_dev;
	/** @bl_dev: pseudo-backlight device for oled panel */
	struct backlight_device *bl_dev;
	/** @panel_info: struct containing panel timing and info */
	const struct d53e6ea8966_panel_info *panel_info;
};

#define NUM_GAMMA_LEVELS	16
#define GAMMA_TABLE_COUNT	23
#define MAX_BRIGHTNESS		(NUM_GAMMA_LEVELS - 1)

#define MCS_ELVSS_ON			0xb1
#define MCS_TEMP_SWIRE			0xb2
#define MCS_PASSWORD_0			0xf0
#define MCS_PASSWORD_1			0xf1
#define MCS_ANALOG_PWR_CTL_0		0xf4
#define MCS_ANALOG_PWR_CTL_1		0xf5
#define MCS_GTCON_SET			0xf7
#define MCS_GATELESS_SIGNAL_SET		0xf8
#define MCS_SET_GAMMA			0xf9

static inline struct d53e6ea8966 *to_d53e6ea8966(struct drm_panel *panel)
{
	return container_of(panel, struct d53e6ea8966, panel);
}

/* Table of gamma values provided in datasheet */
static u8 ams495qa01_gamma[NUM_GAMMA_LEVELS][GAMMA_TABLE_COUNT] = {
	{0x01, 0x79, 0x78, 0x8d, 0xd9, 0xdf, 0xd5, 0xcb, 0xcf, 0xc5,
	 0xe5, 0xe0, 0xe4, 0xdc, 0xb8, 0xd4, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x7d, 0x7c, 0x92, 0xd7, 0xdd, 0xd2, 0xcb, 0xd0, 0xc6,
	 0xe5, 0xe1, 0xe3, 0xda, 0xbd, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x7f, 0x7e, 0x95, 0xd7, 0xde, 0xd2, 0xcb, 0xcf, 0xc5,
	 0xe5, 0xe3, 0xe3, 0xda, 0xbf, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x82, 0x81, 0x99, 0xd6, 0xdd, 0xd1, 0xca, 0xcf, 0xc3,
	 0xe4, 0xe3, 0xe3, 0xda, 0xc2, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x84, 0x83, 0x9b, 0xd7, 0xde, 0xd2, 0xc8, 0xce, 0xc2,
	 0xe4, 0xe3, 0xe2, 0xd9, 0xc3, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x87, 0x86, 0x9f, 0xd6, 0xdd, 0xd1, 0xc7, 0xce, 0xc1,
	 0xe4, 0xe3, 0xe2, 0xd9, 0xc6, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x89, 0x89, 0xa2, 0xd5, 0xdb, 0xcf, 0xc8, 0xcf, 0xc2,
	 0xe3, 0xe3, 0xe1, 0xd9, 0xc7, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x8b, 0x8b, 0xa5, 0xd5, 0xdb, 0xcf, 0xc7, 0xce, 0xc0,
	 0xe3, 0xe3, 0xe1, 0xd8, 0xc7, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x8d, 0x8d, 0xa7, 0xd5, 0xdb, 0xcf, 0xc6, 0xce, 0xc0,
	 0xe4, 0xe4, 0xe1, 0xd7, 0xc8, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x8f, 0x8f, 0xaa, 0xd4, 0xdb, 0xce, 0xc6, 0xcd, 0xbf,
	 0xe3, 0xe3, 0xe1, 0xd7, 0xca, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x91, 0x91, 0xac, 0xd3, 0xda, 0xce, 0xc5, 0xcd, 0xbe,
	 0xe3, 0xe3, 0xe0, 0xd7, 0xca, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x93, 0x93, 0xaf, 0xd3, 0xda, 0xcd, 0xc5, 0xcd, 0xbe,
	 0xe2, 0xe3, 0xdf, 0xd6, 0xca, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x95, 0x95, 0xb1, 0xd2, 0xd9, 0xcc, 0xc4, 0xcd, 0xbe,
	 0xe2, 0xe3, 0xdf, 0xd7, 0xcc, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x99, 0x99, 0xb6, 0xd1, 0xd9, 0xcc, 0xc3, 0xcb, 0xbc,
	 0xe2, 0xe4, 0xdf, 0xd6, 0xcc, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x9c, 0x9c, 0xba, 0xd0, 0xd8, 0xcb, 0xc3, 0xcb, 0xbb,
	 0xe2, 0xe4, 0xdf, 0xd6, 0xce, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
	{0x01, 0x9f, 0x9f, 0xbe, 0xcf, 0xd7, 0xc9, 0xc2, 0xcb, 0xbb,
	 0xe1, 0xe3, 0xde, 0xd6, 0xd0, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
	 0x00, 0x2f},
};

/*
 * Table of elvss values provided in datasheet and corresponds to
 * gamma values.
 */
static u8 ams495qa01_elvss[NUM_GAMMA_LEVELS] = {
	0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15,
	0x15, 0x15, 0x14, 0x14, 0x13, 0x12,
};

static int ams495qa01_update_gamma(struct mipi_dbi *dbi, int brightness)
{
	int tmp = brightness;

	mipi_dbi_command_buf(dbi, MCS_SET_GAMMA, ams495qa01_gamma[tmp],
			     ARRAY_SIZE(ams495qa01_gamma[tmp]));
	mipi_dbi_command(dbi, MCS_SET_GAMMA, 0x00);

	/* Undocumented command */
	mipi_dbi_command(dbi, 0x26, 0x00);

	mipi_dbi_command(dbi, MCS_TEMP_SWIRE, ams495qa01_elvss[tmp]);

	return 0;
}

static void ams495qa01_panel_init(struct d53e6ea8966 *db)
{
	struct mipi_dbi *dbi = &db->dbi;

	mipi_dbi_command(dbi, MCS_PASSWORD_0, 0x5a, 0x5a);
	mipi_dbi_command(dbi, MCS_PASSWORD_1, 0x5a, 0x5a);

	/* Undocumented commands */
	mipi_dbi_command(dbi, 0xb0, 0x02);
	mipi_dbi_command(dbi, 0xf3, 0x3b);

	mipi_dbi_command(dbi, MCS_ANALOG_PWR_CTL_0, 0x33, 0x42, 0x00, 0x08);
	mipi_dbi_command(dbi, MCS_ANALOG_PWR_CTL_1, 0x00, 0x06, 0x26, 0x35, 0x03);

	/* Undocumented commands */
	mipi_dbi_command(dbi, 0xf6, 0x02);
	mipi_dbi_command(dbi, 0xc6, 0x0b, 0x00, 0x00, 0x3c, 0x00, 0x22,
			 0x00, 0x00, 0x00, 0x00);

	mipi_dbi_command(dbi, MCS_GTCON_SET, 0x20);
	mipi_dbi_command(dbi, MCS_TEMP_SWIRE, 0x06, 0x06, 0x06, 0x06);
	mipi_dbi_command(dbi, MCS_ELVSS_ON, 0x07, 0x00, 0x10);
	mipi_dbi_command(dbi, MCS_GATELESS_SIGNAL_SET, 0x7f, 0x7a,
			 0x89, 0x67, 0x26, 0x38, 0x00, 0x00, 0x09,
			 0x67, 0x70, 0x88, 0x7a, 0x76, 0x05, 0x09,
			 0x23, 0x23, 0x23);

	/* Undocumented commands */
	mipi_dbi_command(dbi, 0xb5, 0xff, 0xef, 0x35, 0x42, 0x0d, 0xd7,
			 0xff, 0x07, 0xff, 0xff, 0xfd, 0x00, 0x01,
			 0xff, 0x05, 0x12, 0x0f, 0xff, 0xff, 0xff,
			 0xff);
	mipi_dbi_command(dbi, 0xb4, 0x15);
	mipi_dbi_command(dbi, 0xb3, 0x00);

	ams495qa01_update_gamma(dbi, MAX_BRIGHTNESS);
}

static int d53e6ea8966_prepare(struct drm_panel *panel)
{
	struct d53e6ea8966 *db = to_d53e6ea8966(panel);
	int ret;

	/* Power up */
	ret = regulator_enable(db->reg_vdd);
	if (ret) {
		dev_err(db->dev, "failed to enable vdd regulator: %d\n", ret);
		return ret;
	}

	if (db->reg_elvdd) {
		ret = regulator_enable(db->reg_elvdd);
		if (ret) {
			dev_err(db->dev,
				"failed to enable elvdd regulator: %d\n", ret);
			regulator_disable(db->reg_vdd);
			return ret;
		}
	}

	/* Enable */
	if (db->enable)
		gpiod_set_value_cansleep(db->enable, 1);

	msleep(50);

	/* Reset */
	gpiod_set_value_cansleep(db->reset, 1);
	usleep_range(1000, 5000);
	gpiod_set_value_cansleep(db->reset, 0);
	msleep(20);

	db->panel_info->panel_init_seq(db);

	return 0;
}

static int d53e6ea8966_enable(struct drm_panel *panel)
{
	struct d53e6ea8966 *db = to_d53e6ea8966(panel);
	struct mipi_dbi *dbi = &db->dbi;

	mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
	msleep(200);
	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
	usleep_range(10000, 15000);

	return 0;
}

static int d53e6ea8966_disable(struct drm_panel *panel)
{
	struct d53e6ea8966 *db = to_d53e6ea8966(panel);
	struct mipi_dbi *dbi = &db->dbi;

	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);
	msleep(20);
	mipi_dbi_command(dbi, MIPI_DCS_ENTER_SLEEP_MODE);
	msleep(100);

	return 0;
}

static int d53e6ea8966_unprepare(struct drm_panel *panel)
{
	struct d53e6ea8966 *db = to_d53e6ea8966(panel);

	if (db->enable)
		gpiod_set_value_cansleep(db->enable, 0);

	gpiod_set_value_cansleep(db->reset, 1);

	if (db->reg_elvdd)
		regulator_disable(db->reg_elvdd);

	regulator_disable(db->reg_vdd);
	msleep(100);

	return 0;
}

static int d53e6ea8966_get_modes(struct drm_panel *panel,
				 struct drm_connector *connector)
{
	struct d53e6ea8966 *db = to_d53e6ea8966(panel);
	const struct d53e6ea8966_panel_info *panel_info = db->panel_info;
	struct drm_display_mode *mode;
	static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
	unsigned int i;

	for (i = 0; i < panel_info->num_modes; i++) {
		mode = drm_mode_duplicate(connector->dev,
					  &panel_info->display_modes[i]);
		if (!mode)
			return -ENOMEM;

		drm_mode_set_name(mode);
		drm_mode_probed_add(connector, mode);
	}

	connector->display_info.bpc = 8;
	connector->display_info.width_mm = panel_info->width_mm;
	connector->display_info.height_mm = panel_info->height_mm;
	connector->display_info.bus_flags = panel_info->bus_flags;

	drm_display_info_set_bus_formats(&connector->display_info,
					 &bus_format, 1);

	return 1;
}

static const struct drm_panel_funcs d53e6ea8966_panel_funcs = {
	.disable = d53e6ea8966_disable,
	.enable = d53e6ea8966_enable,
	.get_modes = d53e6ea8966_get_modes,
	.prepare = d53e6ea8966_prepare,
	.unprepare = d53e6ea8966_unprepare,
};

static int ams495qa01_set_brightness(struct backlight_device *bd)
{
	struct d53e6ea8966 *db = bl_get_data(bd);
	struct mipi_dbi *dbi = &db->dbi;
	int brightness = backlight_get_brightness(bd);

	ams495qa01_update_gamma(dbi, brightness);

	return 0;
}

static const struct backlight_ops ams495qa01_backlight_ops = {
	.update_status	= ams495qa01_set_brightness,
};

static int ams495qa01_backlight_register(struct d53e6ea8966 *db)
{
	struct backlight_properties props = {
		.type		= BACKLIGHT_RAW,
		.brightness	= MAX_BRIGHTNESS,
		.max_brightness = MAX_BRIGHTNESS,
	};
	struct device *dev = db->dev;
	int ret = 0;

	db->bl_dev = devm_backlight_device_register(dev, "panel", dev, db,
						    &ams495qa01_backlight_ops,
						    &props);
	if (IS_ERR(db->bl_dev)) {
		ret = PTR_ERR(db->bl_dev);
		dev_err(dev, "error registering backlight device (%d)\n", ret);
	}

	return ret;
}

static int d53e6ea8966_probe(struct spi_device *spi)
{
	struct device *dev = &spi->dev;
	struct mipi_dsi_host *dsi_host;
	struct d53e6ea8966 *db;
	int ret;
	struct mipi_dsi_device_info info = {
		.type = "d53e6ea8966",
		.channel = 0,
		.node = NULL,
	};

	db = devm_kzalloc(dev, sizeof(*db), GFP_KERNEL);
	if (!db)
		return -ENOMEM;

	spi_set_drvdata(spi, db);

	db->dev = dev;

	db->panel_info = of_device_get_match_data(dev);
	if (!db->panel_info)
		return -EINVAL;

	db->reg_vdd = devm_regulator_get(dev, "vdd");
	if (IS_ERR(db->reg_vdd))
		return dev_err_probe(dev, PTR_ERR(db->reg_vdd),
				     "Failed to get vdd supply\n");

	db->reg_elvdd = devm_regulator_get_optional(dev, "elvdd");
	if (IS_ERR(db->reg_elvdd))
		db->reg_elvdd = NULL;

	db->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
	if (IS_ERR(db->reset)) {
		ret = PTR_ERR(db->reset);
		return dev_err_probe(dev, ret, "no RESET GPIO\n");
	}

	db->enable = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
	if (IS_ERR(db->enable)) {
		ret = PTR_ERR(db->enable);
		return dev_err_probe(dev, ret, "cannot get ENABLE GPIO\n");
	}

	ret = mipi_dbi_spi_init(spi, &db->dbi, NULL);
	if (ret)
		return dev_err_probe(dev, ret, "MIPI DBI init failed\n");

	dsi_host = drm_of_get_dsi_bus(dev);
	if (IS_ERR(dsi_host)) {
		ret = PTR_ERR(dsi_host);
		return dev_err_probe(dev, ret, "Error attaching DSI bus\n");
	}

	db->dsi_dev = devm_mipi_dsi_device_register_full(dev, dsi_host, &info);
	if (IS_ERR(db->dsi_dev)) {
		dev_err(dev, "failed to register dsi device: %ld\n",
			PTR_ERR(db->dsi_dev));
		return PTR_ERR(db->dsi_dev);
	}

	db->dsi_dev->lanes = 2;
	db->dsi_dev->format = MIPI_DSI_FMT_RGB888;
	db->dsi_dev->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
			  MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_NO_EOT_PACKET;

	drm_panel_init(&db->panel, dev, &d53e6ea8966_panel_funcs,
		       DRM_MODE_CONNECTOR_DSI);

	if (db->panel_info->backlight_register) {
		ret = db->panel_info->backlight_register(db);
		if (ret < 0)
			return ret;
		db->panel.backlight = db->bl_dev;
	}

	drm_panel_add(&db->panel);

	ret = devm_mipi_dsi_attach(dev, db->dsi_dev);
	if (ret < 0) {
		dev_err(dev, "mipi_dsi_attach failed: %d\n", ret);
		drm_panel_remove(&db->panel);
		return ret;
	}

	return 0;
}

static void d53e6ea8966_remove(struct spi_device *spi)
{
	struct d53e6ea8966 *db = spi_get_drvdata(spi);

	drm_panel_remove(&db->panel);
}

static const struct drm_display_mode ams495qa01_modes[] = {
	{ /* 60hz */
		.clock = 33500,
		.hdisplay = 960,
		.hsync_start = 960 + 10,
		.hsync_end = 960 + 10 + 2,
		.htotal = 960 + 10 + 2 + 10,
		.vdisplay = 544,
		.vsync_start = 544 + 10,
		.vsync_end = 544 + 10 + 2,
		.vtotal = 544 + 10 + 2 + 10,
		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
		.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
		},
	{ /* 50hz */
		.clock = 27800,
		.hdisplay = 960,
		.hsync_start = 960 + 10,
		.hsync_end = 960 + 10 + 2,
		.htotal = 960 + 10 + 2 + 10,
		.vdisplay = 544,
		.vsync_start = 544 + 10,
		.vsync_end = 544 + 10 + 2,
		.vtotal = 544 + 10 + 2 + 10,
		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
		.type = DRM_MODE_TYPE_DRIVER,
	},
};

static const struct d53e6ea8966_panel_info ams495qa01_info = {
	.display_modes = ams495qa01_modes,
	.num_modes = ARRAY_SIZE(ams495qa01_modes),
	.width_mm = 117,
	.height_mm = 74,
	.bus_flags = DRM_BUS_FLAG_DE_LOW | DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
	.panel_init_seq = ams495qa01_panel_init,
	.backlight_register = ams495qa01_backlight_register,
};

static const struct of_device_id d53e6ea8966_match[] = {
	{ .compatible = "samsung,ams495qa01", .data = &ams495qa01_info },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, d53e6ea8966_match);

static const struct spi_device_id d53e6ea8966_ids[] = {
	{ "ams495qa01", 0 },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(spi, d53e6ea8966_ids);

static struct spi_driver d53e6ea8966_driver = {
	.driver		= {
		.name	= "d53e6ea8966-panel",
		.of_match_table = d53e6ea8966_match,
	},
	.id_table	= d53e6ea8966_ids,
	.probe		= d53e6ea8966_probe,
	.remove		= d53e6ea8966_remove,
};
module_spi_driver(d53e6ea8966_driver);

MODULE_AUTHOR("Chris Morgan <macromorgan@hotmail.com>");
MODULE_DESCRIPTION("Magnachip d53e6ea8966 panel driver");
MODULE_LICENSE("GPL");